update

Made it really stupidly clear that this is vibecoded

boards/t-deck_pro_max.json

@@ -0,0 +1,40 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "esp32s3_out.ld",
+      "memory_type": "qio_qspi",
+      "partitions": "default_16MB.csv"
+    },
+    "core": "esp32",
+    "extra_flags": [
+      "-DBOARD_HAS_PSRAM",
+      "-DARDUINO_USB_CDC_ON_BOOT=1",
+      "-DARDUINO_USB_MODE=1",
+      "-DARDUINO_RUNNING_CORE=1",
+      "-DARDUINO_EVENT_RUNNING_CORE=1"
+    ],
+    "f_cpu": "240000000L",
+    "f_flash": "80000000L",
+    "flash_mode": "qio",
+    "hwids": [["0x303A", "0x1001"]],
+    "mcu": "esp32s3",
+    "variant": "esp32s3"
+  },
+  "connectivity": ["wifi", "bluetooth", "lora"],
+  "debug": {
+    "default_tool": "esp-builtin",
+    "onboard_tools": ["esp-builtin"],
+    "openocd_target": "esp32s3.cfg"
+  },
+  "frameworks": ["arduino", "espidf"],
+  "name": "LilyGo T-Deck Pro MAX (16MB Flash 8MB QSPI PSRAM)",
+  "upload": {
+    "flash_size": "16MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 16777216,
+    "require_upload_port": true,
+    "speed": 921600
+  },
+  "url": "https://www.lilygo.cc/products/t-deck-pro",
+  "vendor": "LilyGo"
+}

examples/companion_radio/main.cpp

@@ -2564,6 +2564,21 @@ void handleKeyboardInput() {
   // Still read the key above to clear the TCA8418 buffer.
   if (ui_task.isLocked()) return;
 
+  // Alt+B backlight toggle (T-Deck Pro MAX — working front-light on IO41)
+  // Cycles: off → low → medium → full → off
+  // Works from any screen; processed before anything else so it never
+  // leaks into compose buffers or screen handlers.
+  #ifdef LilyGo_TDeck_Pro_Max
+  if (key == KB_KEY_BACKLIGHT) {
+    static uint8_t blLevel = 0;  // 0=off, 1=low, 2=med, 3=full
+    blLevel = (blLevel + 1) & 3;
+    const uint8_t levels[] = {0, 64, 160, 255};
+    board.backlightSetBrightness(levels[blLevel]);
+    Serial.printf("Backlight: level %d (%d/255)\n", blLevel, levels[blLevel]);
+    return;
+  }
+  #endif
+
   // Dismiss boot navigation hint on any keypress
   if (ui_task.isHintActive()) {
     ui_task.dismissBootHint();

variants/lilygo_tdeck_pro_max/TDeckProMaxBoard.cpp

@@ -0,0 +1,347 @@
+#include <Arduino.h>
+#include "variant.h"
+#include "TDeckProMaxBoard.h"
+#include <Mesh.h>  // For MESH_DEBUG_PRINTLN
+
+// LEDC channel for e-ink backlight PWM (Arduino ESP32 core 2.x channel-based API)
+#ifdef PIN_EINK_BL
+  #define EINK_BL_LEDC_CHANNEL 0
+#endif
+
+// =============================================================================
+// TDeckProMaxBoard::begin() — Boot sequence for T-Deck Pro MAX V0.1
+//
+// Critical ordering:
+//   1. I2C bus init (XL9555, BQ27220, and all sensors share this bus)
+//   2. XL9555 init (must be up before ANY peripheral that depends on it)
+//   3. Touch reset pulse via XL9555 (needed before touch driver init)
+//   4. Keyboard reset pulse via XL9555 (clean keyboard state)
+//   5. LoRa power enable via XL9555 (must be on before SPI radio init)
+//   6. GPS power + UART init
+//   7. Parent class init (ESP32Board::begin)
+//   8. LoRa SPI pin config + deep sleep wake handling
+//   9. BQ27220 fuel gauge check
+//  10. Low-voltage protection
+//
+// NOTE: We do NOT call TDeckBoard::begin() — we reimplement the boot sequence
+// to handle XL9555-routed pins. BQ27220 methods are inherited unchanged.
+// =============================================================================
+
+void TDeckProMaxBoard::begin() {
+
+  MESH_DEBUG_PRINTLN("TDeckProMaxBoard::begin() - T-Deck Pro MAX V0.1");
+
+  // ------ Step 1: I2C bus ------
+  // All I2C devices (XL9555, BQ27220, TCA8418, CST328, DRV2605, ES8311,
+  // BQ25896, BHI260AP) share SDA=13, SCL=14.
+  Wire.begin(I2C_SDA, I2C_SCL);
+  Wire.setClock(100000);  // 100kHz — safe for all devices on the bus
+  MESH_DEBUG_PRINTLN("  I2C initialized (SDA=%d SCL=%d)", I2C_SDA, I2C_SCL);
+
+  // ------ Step 2: XL9555 I/O Expander ------
+  // This must happen before anything that needs peripheral power or resets.
+  if (!xl9555_init()) {
+    Serial.println("CRITICAL: XL9555 init failed — peripherals will not work!");
+    // Continue anyway; some things (display, keyboard INT) might still work
+    // without XL9555, but LoRa/GPS/modem will be dead.
+  }
+
+  // ------ Step 3: Touch reset pulse ------
+  // The touch controller (CST328) needs a clean reset via XL9555 IO07
+  // before the touch driver tries to communicate with it.
+  touchReset();
+
+  // ------ Step 4: Keyboard reset pulse ------
+  keyboardReset();
+
+  // ------ Step 5: Parent class init ------
+  // ESP32Board::begin() handles common ESP32 setup.
+  // We skip TDeckBoard::begin() because it uses PIN_PERF_POWERON and
+  // direct GPIO for LoRa/GPS power that don't exist on MAX.
+  ESP32Board::begin();
+
+  // ------ Step 6: GPS UART init ------
+  // GPS power was already enabled by XL9555 boot defaults (GPS_EN HIGH).
+  // Now init the UART with the MAX-specific pins.
+  #if HAS_GPS
+    Serial2.begin(GPS_BAUDRATE, SERIAL_8N1, GPS_RX_PIN, GPS_TX_PIN);
+    MESH_DEBUG_PRINTLN("  GPS Serial2 initialized (RX=%d TX=%d @ %d baud)",
+                       GPS_RX_PIN, GPS_TX_PIN, GPS_BAUDRATE);
+  #endif
+
+  // ------ Step 7: Configure user button ------
+  pinMode(PIN_USER_BTN, INPUT);
+
+  // ------ Step 8: Configure LoRa SPI pins ------
+  // LoRa power is already enabled via XL9555 (LORA_EN HIGH in boot defaults).
+  pinMode(P_LORA_MISO, INPUT_PULLUP);
+
+  // ------ Step 9: Handle wake from deep sleep ------
+  esp_reset_reason_t reason = esp_reset_reason();
+  if (reason == ESP_RST_DEEPSLEEP) {
+    uint64_t wakeup_source = esp_sleep_get_ext1_wakeup_status();
+    if (wakeup_source & (1ULL << P_LORA_DIO_1)) {
+      startup_reason = BD_STARTUP_RX_PACKET;
+    }
+    rtc_gpio_hold_dis((gpio_num_t)P_LORA_NSS);
+    rtc_gpio_deinit((gpio_num_t)P_LORA_DIO_1);
+  }
+
+  // ------ Step 10: BQ27220 fuel gauge ------
+  #if HAS_BQ27220
+    uint16_t voltage = getBattMilliVolts();
+    MESH_DEBUG_PRINTLN("  Battery voltage: %d mV", voltage);
+    configureFuelGauge();   // Inherited from TDeckBoard — sets 1500 mAh
+  #endif
+
+  // ------ Step 11: Early low-voltage protection ------
+  #if HAS_BQ27220 && defined(AUTO_SHUTDOWN_MILLIVOLTS)
+  {
+    uint16_t bootMv = getBattMilliVolts();
+    if (bootMv > 0 && bootMv < AUTO_SHUTDOWN_MILLIVOLTS) {
+      Serial.printf("CRITICAL: Boot voltage %dmV < %dmV — sleeping immediately\n",
+                    bootMv, AUTO_SHUTDOWN_MILLIVOLTS);
+      esp_sleep_disable_wakeup_source(ESP_SLEEP_WAKEUP_ALL);
+      esp_sleep_enable_ext1_wakeup(1ULL << PIN_USER_BTN, ESP_EXT1_WAKEUP_ANY_HIGH);
+      esp_deep_sleep_start();
+    }
+  }
+  #endif
+
+  // ------ Step 12: E-ink backlight (working on MAX!) ------
+  // Configure LEDC PWM for backlight brightness control.
+  // Start with backlight OFF — UI code can enable it when needed.
+  #ifdef PIN_EINK_BL
+    // Arduino ESP32 core 2.x uses channel-based LEDC API
+    ledcSetup(EINK_BL_LEDC_CHANNEL, 1000, 8);  // Channel 0, 1kHz, 8-bit resolution
+    ledcAttachPin(PIN_EINK_BL, EINK_BL_LEDC_CHANNEL);
+    ledcWrite(EINK_BL_LEDC_CHANNEL, 0);        // Off by default
+    MESH_DEBUG_PRINTLN("  Backlight PWM configured on IO%d", PIN_EINK_BL);
+  #endif
+
+  MESH_DEBUG_PRINTLN("TDeckProMaxBoard::begin() - complete");
+}
+
+
+// =============================================================================
+// XL9555 I/O Expander — Lightweight I2C Driver
+// =============================================================================
+
+bool TDeckProMaxBoard::xl9555_writeReg(uint8_t reg, uint8_t val) {
+  Wire.beginTransmission(I2C_ADDR_XL9555);
+  Wire.write(reg);
+  Wire.write(val);
+  return Wire.endTransmission() == 0;
+}
+
+uint8_t TDeckProMaxBoard::xl9555_readReg(uint8_t reg) {
+  Wire.beginTransmission(I2C_ADDR_XL9555);
+  Wire.write(reg);
+  Wire.endTransmission(false);
+  Wire.requestFrom((uint8_t)I2C_ADDR_XL9555, (uint8_t)1);
+  return Wire.available() ? Wire.read() : 0xFF;
+}
+
+bool TDeckProMaxBoard::xl9555_init() {
+  MESH_DEBUG_PRINTLN("  XL9555: Initializing I/O expander at 0x%02X", I2C_ADDR_XL9555);
+
+  // Verify XL9555 is present on the bus
+  Wire.beginTransmission(I2C_ADDR_XL9555);
+  if (Wire.endTransmission() != 0) {
+    Serial.println("  XL9555: NOT FOUND on I2C bus!");
+    _xlReady = false;
+    return false;
+  }
+
+  // Set ALL pins as outputs (config register: 0 = output)
+  // Port 0 (pins 0-7): all output
+  if (!xl9555_writeReg(XL9555_REG_CONFIG_0, 0x00)) return false;
+  // Port 1 (pins 8-15): all output
+  if (!xl9555_writeReg(XL9555_REG_CONFIG_1, 0x00)) return false;
+
+  // Apply boot defaults
+  _xlPort0 = XL9555_BOOT_PORT0;
+  _xlPort1 = XL9555_BOOT_PORT1;
+  if (!xl9555_writeReg(XL9555_REG_OUTPUT_0, _xlPort0)) return false;
+  if (!xl9555_writeReg(XL9555_REG_OUTPUT_1, _xlPort1)) return false;
+
+  _xlReady = true;
+
+  MESH_DEBUG_PRINTLN("  XL9555: Ready (Port0=0x%02X Port1=0x%02X)", _xlPort0, _xlPort1);
+  MESH_DEBUG_PRINTLN("  XL9555: LoRa=%s GPS=%s 1V8=%s Modem=%s Antenna=%s",
+                     (_xlPort0 & (1 << XL_PIN_LORA_EN)) ? "ON" : "OFF",
+                     (_xlPort0 & (1 << XL_PIN_GPS_EN)) ? "ON" : "OFF",
+                     (_xlPort0 & (1 << XL_PIN_1V8_EN)) ? "ON" : "OFF",
+                     (_xlPort0 & (1 << XL_PIN_6609_EN)) ? "ON" : "OFF",
+                     (_xlPort0 & (1 << XL_PIN_LORA_SEL)) ? "internal" : "external");
+
+  return true;
+}
+
+void TDeckProMaxBoard::xl9555_digitalWrite(uint8_t pin, bool value) {
+  if (!_xlReady) return;
+
+  if (pin < 8) {
+    // Port 0
+    if (value) _xlPort0 |= (1 << pin);
+    else       _xlPort0 &= ~(1 << pin);
+    xl9555_writeReg(XL9555_REG_OUTPUT_0, _xlPort0);
+  } else if (pin < 16) {
+    // Port 1 (subtract 8 for bit position)
+    uint8_t bit = pin - 8;
+    if (value) _xlPort1 |= (1 << bit);
+    else       _xlPort1 &= ~(1 << bit);
+    xl9555_writeReg(XL9555_REG_OUTPUT_1, _xlPort1);
+  }
+}
+
+bool TDeckProMaxBoard::xl9555_digitalRead(uint8_t pin) const {
+  if (pin < 8) return (_xlPort0 >> pin) & 1;
+  if (pin < 16) return (_xlPort1 >> (pin - 8)) & 1;
+  return false;
+}
+
+void TDeckProMaxBoard::xl9555_writePort0(uint8_t val) {
+  _xlPort0 = val;
+  if (_xlReady) xl9555_writeReg(XL9555_REG_OUTPUT_0, val);
+}
+
+void TDeckProMaxBoard::xl9555_writePort1(uint8_t val) {
+  _xlPort1 = val;
+  if (_xlReady) xl9555_writeReg(XL9555_REG_OUTPUT_1, val);
+}
+
+
+// =============================================================================
+// High-level peripheral control
+// =============================================================================
+
+// ---- Modem (A7682E) ----
+
+void TDeckProMaxBoard::modemPowerOn() {
+  MESH_DEBUG_PRINTLN("  XL9555: Modem power ON (6609_EN HIGH)");
+  xl9555_digitalWrite(XL_PIN_6609_EN, HIGH);
+  delay(100);  // Allow SGM6609 boost to stabilise
+}
+
+void TDeckProMaxBoard::modemPowerOff() {
+  MESH_DEBUG_PRINTLN("  XL9555: Modem power OFF (6609_EN LOW)");
+  xl9555_digitalWrite(XL_PIN_6609_EN, LOW);
+}
+
+void TDeckProMaxBoard::modemPwrkeyPulse() {
+  // A7682E power-on sequence: pulse PWRKEY LOW for >= 500ms
+  // (Some datasheets say pull HIGH then LOW; LilyGo factory sets HIGH then toggles.)
+  MESH_DEBUG_PRINTLN("  XL9555: Modem PWRKEY pulse");
+  xl9555_digitalWrite(XL_PIN_PWRKEY_EN, HIGH);
+  delay(100);
+  xl9555_digitalWrite(XL_PIN_PWRKEY_EN, LOW);
+  delay(1200);
+  xl9555_digitalWrite(XL_PIN_PWRKEY_EN, HIGH);
+}
+
+// ---- Audio output selection ----
+
+void TDeckProMaxBoard::selectAudioES8311() {
+  MESH_DEBUG_PRINTLN("  XL9555: Audio select → ES8311");
+  xl9555_digitalWrite(XL_PIN_AUDIO_SEL, LOW);
+}
+
+void TDeckProMaxBoard::selectAudioModem() {
+  MESH_DEBUG_PRINTLN("  XL9555: Audio select → A7682E");
+  xl9555_digitalWrite(XL_PIN_AUDIO_SEL, HIGH);
+}
+
+void TDeckProMaxBoard::amplifierEnable() {
+  xl9555_digitalWrite(XL_PIN_AMPLIFIER, HIGH);
+}
+
+void TDeckProMaxBoard::amplifierDisable() {
+  xl9555_digitalWrite(XL_PIN_AMPLIFIER, LOW);
+}
+
+// ---- LoRa antenna selection ----
+
+void TDeckProMaxBoard::loraAntennaInternal() {
+  MESH_DEBUG_PRINTLN("  XL9555: LoRa antenna → internal");
+  xl9555_digitalWrite(XL_PIN_LORA_SEL, HIGH);
+}
+
+void TDeckProMaxBoard::loraAntennaExternal() {
+  MESH_DEBUG_PRINTLN("  XL9555: LoRa antenna → external");
+  xl9555_digitalWrite(XL_PIN_LORA_SEL, LOW);
+}
+
+// ---- Motor (DRV2605) ----
+
+void TDeckProMaxBoard::motorEnable() {
+  xl9555_digitalWrite(XL_PIN_MOTOR_EN, HIGH);
+}
+
+void TDeckProMaxBoard::motorDisable() {
+  xl9555_digitalWrite(XL_PIN_MOTOR_EN, LOW);
+}
+
+// ---- Touch reset ----
+
+void TDeckProMaxBoard::touchReset() {
+  if (!_xlReady) return;
+  MESH_DEBUG_PRINTLN("  XL9555: Touch reset pulse");
+  xl9555_digitalWrite(XL_PIN_TOUCH_RST, LOW);
+  delay(20);
+  xl9555_digitalWrite(XL_PIN_TOUCH_RST, HIGH);
+  delay(50);  // Allow touch controller to come out of reset
+}
+
+// ---- Keyboard reset ----
+
+void TDeckProMaxBoard::keyboardReset() {
+  if (!_xlReady) return;
+  MESH_DEBUG_PRINTLN("  XL9555: Keyboard reset pulse");
+  xl9555_digitalWrite(XL_PIN_KEY_RST, LOW);
+  delay(20);
+  xl9555_digitalWrite(XL_PIN_KEY_RST, HIGH);
+  delay(50);
+}
+
+// ---- GPS power ----
+
+void TDeckProMaxBoard::gpsPowerOn() {
+  xl9555_digitalWrite(XL_PIN_GPS_EN, HIGH);
+  delay(100);
+}
+
+void TDeckProMaxBoard::gpsPowerOff() {
+  xl9555_digitalWrite(XL_PIN_GPS_EN, LOW);
+}
+
+// ---- LoRa power ----
+
+void TDeckProMaxBoard::loraPowerOn() {
+  xl9555_digitalWrite(XL_PIN_LORA_EN, HIGH);
+  delay(10);
+}
+
+void TDeckProMaxBoard::loraPowerOff() {
+  xl9555_digitalWrite(XL_PIN_LORA_EN, LOW);
+}
+
+// ---- E-ink backlight (working on MAX!) ----
+
+void TDeckProMaxBoard::backlightOn() {
+  #ifdef PIN_EINK_BL
+    ledcWrite(EINK_BL_LEDC_CHANNEL, 255);
+  #endif
+}
+
+void TDeckProMaxBoard::backlightOff() {
+  #ifdef PIN_EINK_BL
+    ledcWrite(EINK_BL_LEDC_CHANNEL, 0);
+  #endif
+}
+
+void TDeckProMaxBoard::backlightSetBrightness(uint8_t duty) {
+  #ifdef PIN_EINK_BL
+    ledcWrite(EINK_BL_LEDC_CHANNEL, duty);
+  #endif
+}

variants/lilygo_tdeck_pro_max/TDeckProMaxBoard.h

@@ -0,0 +1,108 @@
+#pragma once
+
+// =============================================================================
+// TDeckProMaxBoard — Board support for LilyGo T-Deck Pro MAX V0.1
+//
+// Extends TDeckBoard (which provides all BQ27220 fuel gauge methods) with:
+//   - XL9555 I/O expander initialisation and control
+//   - XL9555-routed peripheral power management
+//   - Touch/keyboard reset via XL9555
+//   - Modem power/PWRKEY via XL9555
+//   - LoRa antenna selection via XL9555
+//   - Audio output mux (ES8311 vs A7682E) via XL9555
+//   - Speaker amplifier enable via XL9555
+//
+// The XL9555 must be initialised before LoRa, GPS, modem, or touch are used.
+// All power enables, resets, and switches go through I2C — not direct GPIO.
+// =============================================================================
+
+#include "variant.h"
+#include "TDeckBoard.h"   // Inherits BQ27220 fuel gauge, deep sleep, power management
+
+class TDeckProMaxBoard : public TDeckBoard {
+public:
+  void begin();
+
+  const char* getManufacturerName() const {
+    return "LilyGo T-Deck Pro MAX";
+  }
+
+  // -------------------------------------------------------------------------
+  // XL9555 I/O Expander — lightweight inline driver
+  //
+  // The XL9555 has 16 I/O pins across two 8-bit ports.
+  // Pin 0-7 = Port 0, Pin 8-15 = Port 1.
+  // We shadow the output state in _xlPort0/_xlPort1 to allow
+  // single-bit set/clear without read-modify-write over I2C.
+  // -------------------------------------------------------------------------
+
+  // Initialise XL9555: set all used pins as outputs, apply boot defaults.
+  // Returns true if I2C communication with XL9555 succeeded.
+  bool xl9555_init();
+
+  // Set a single XL9555 pin HIGH or LOW (pin 0-15).
+  void xl9555_digitalWrite(uint8_t pin, bool value);
+
+  // Read the current output state of a pin (from shadow, not I2C read).
+  bool xl9555_digitalRead(uint8_t pin) const;
+
+  // Write raw port values (for batch updates).
+  void xl9555_writePort0(uint8_t val);
+  void xl9555_writePort1(uint8_t val);
+
+  // -------------------------------------------------------------------------
+  // High-level peripheral control (delegates to XL9555)
+  // -------------------------------------------------------------------------
+
+  // Modem (A7682E) power control
+  void modemPowerOn();       // Enable SGM6609 boost (6609_EN HIGH)
+  void modemPowerOff();      // Disable SGM6609 boost (6609_EN LOW)
+  void modemPwrkeyPulse();   // Toggle PWRKEY: HIGH 100ms → LOW 1200ms → HIGH
+
+  // Audio output selection
+  void selectAudioES8311();  // AUDIO_SEL LOW → ES8311 output to speaker/headphones
+  void selectAudioModem();   // AUDIO_SEL HIGH → A7682E output to speaker/headphones
+  void amplifierEnable();    // NS4150B amplifier ON (louder speaker)
+  void amplifierDisable();   // NS4150B amplifier OFF (saves power)
+
+  // LoRa antenna selection (SKY13453 RF switch)
+  void loraAntennaInternal();  // LORA_SEL HIGH → internal PCB antenna (default)
+  void loraAntennaExternal();  // LORA_SEL LOW → external IPEX antenna
+
+  // Motor (DRV2605) power
+  void motorEnable();          // MOTOR_EN HIGH
+  void motorDisable();         // MOTOR_EN LOW
+
+  // Touch controller reset via XL9555
+  void touchReset();           // Pulse TOUCH_RST: LOW 20ms → HIGH, then 50ms settle
+
+  // Keyboard reset via XL9555
+  void keyboardReset();        // Pulse KEY_RST: LOW 20ms → HIGH, then 50ms settle
+
+  // GPS power control via XL9555
+  void gpsPowerOn();           // GPS_EN HIGH
+  void gpsPowerOff();          // GPS_EN LOW
+
+  // LoRa power control via XL9555
+  void loraPowerOn();          // LORA_EN HIGH
+  void loraPowerOff();         // LORA_EN LOW
+
+  // -------------------------------------------------------------------------
+  // E-ink front-light control
+  // On MAX, IO41 has a working backlight circuit (boost converter + LEDs).
+  // PWM control for brightness is possible via ledc.
+  // -------------------------------------------------------------------------
+  void backlightOn();
+  void backlightOff();
+  void backlightSetBrightness(uint8_t duty);  // 0-255, via LEDC PWM
+
+private:
+  // Shadow registers for XL9555 output ports (avoid I2C read-modify-write)
+  uint8_t _xlPort0 = XL9555_BOOT_PORT0;
+  uint8_t _xlPort1 = XL9555_BOOT_PORT1;
+  bool    _xlReady = false;
+
+  // Low-level I2C helpers
+  bool xl9555_writeReg(uint8_t reg, uint8_t val);
+  uint8_t xl9555_readReg(uint8_t reg);
+};

variants/lilygo_tdeck_pro_max/Tca8418keyboard.h

@@ -0,0 +1,360 @@
+#pragma once
+
+#include <Arduino.h>
+#include <Wire.h>
+
+// TCA8418 Register addresses
+#define TCA8418_REG_CFG         0x01
+#define TCA8418_REG_INT_STAT    0x02
+#define TCA8418_REG_KEY_LCK_EC  0x03
+#define TCA8418_REG_KEY_EVENT_A 0x04
+#define TCA8418_REG_KP_GPIO1    0x1D
+#define TCA8418_REG_KP_GPIO2    0x1E
+#define TCA8418_REG_KP_GPIO3    0x1F
+#define TCA8418_REG_DEBOUNCE    0x29
+#define TCA8418_REG_GPI_EM1     0x20
+#define TCA8418_REG_GPI_EM2     0x21
+#define TCA8418_REG_GPI_EM3     0x22
+
+// Key codes for special keys
+#define KB_KEY_NONE      0
+#define KB_KEY_BACKSPACE '\b'
+#define KB_KEY_ENTER     '\r'
+#define KB_KEY_SPACE     ' '
+#define KB_KEY_EMOJI     0x01   // Non-printable code for $ key (emoji picker)
+#define KB_KEY_BACKLIGHT 0x02   // Non-printable code for Alt+B (backlight toggle, MAX only)
+
+class TCA8418Keyboard {
+private:
+  uint8_t _addr;
+  TwoWire* _wire;
+  bool _initialized;
+  bool _shiftActive;   // Sticky shift (one-shot or held)
+  bool _shiftConsumed; // Was shift active for the last returned key
+  bool _shiftHeld;     // Shift key physically held down
+  bool _shiftUsedWhileHeld; // Was shift consumed by any key while held
+  bool _altActive;     // Sticky alt (one-shot)
+  bool _symActive;     // Sticky sym (one-shot)
+  unsigned long _lastShiftTime;  // For Shift+key combos
+
+  uint8_t readReg(uint8_t reg) {
+    _wire->beginTransmission(_addr);
+    _wire->write(reg);
+    _wire->endTransmission();
+    _wire->requestFrom(_addr, (uint8_t)1);
+    return _wire->available() ? _wire->read() : 0;
+  }
+
+  void writeReg(uint8_t reg, uint8_t val) {
+    _wire->beginTransmission(_addr);
+    _wire->write(reg);
+    _wire->write(val);
+    _wire->endTransmission();
+  }
+
+  // Map raw key codes to characters (from working reader firmware)
+  char getKeyChar(uint8_t keyCode) {
+    switch (keyCode) {
+      // Row 1 - QWERTYUIOP
+      case 10: return 'q';   // Q (was 97 on different hardware)
+      case 9:  return 'w';
+      case 8:  return 'e';
+      case 7:  return 'r';
+      case 6:  return 't';
+      case 5:  return 'y';
+      case 4:  return 'u';
+      case 3:  return 'i';
+      case 2:  return 'o';
+      case 1:  return 'p';
+      
+      // Row 2 - ASDFGHJKL + Backspace
+      case 20: return 'a';   // A (was 98 on different hardware)
+      case 19: return 's';
+      case 18: return 'd';
+      case 17: return 'f';
+      case 16: return 'g';
+      case 15: return 'h';
+      case 14: return 'j';
+      case 13: return 'k';
+      case 12: return 'l';
+      case 11: return '\b'; // Backspace
+      
+      // Row 3 - Alt ZXCVBNM Sym Enter
+      case 30: return 0;    // Alt - handled separately
+      case 29: return 'z';
+      case 28: return 'x';
+      case 27: return 'c';
+      case 26: return 'v';
+      case 25: return 'b';
+      case 24: return 'n';
+      case 23: return 'm';
+      case 22: return 0;    // Symbol key - handled separately
+      case 21: return '\r'; // Enter
+      
+      // Row 4 - Shift Mic Space Sym Shift
+      case 35: return 0;    // Left shift - handled separately
+      case 34: return 0;    // Mic
+      case 33: return ' ';  // Space
+      case 32: return 0;    // Sym - handled separately
+      case 31: return 0;    // Right shift - handled separately
+      
+      default: return 0;
+    }
+  }
+
+  // Map key with Alt modifier - same as Sym for this keyboard
+  char getAltChar(uint8_t keyCode) {
+    return getSymChar(keyCode);  // Alt does same as Sym
+  }
+
+  // Map key with Sym modifier - based on actual T-Deck Pro keyboard silk-screen
+  char getSymChar(uint8_t keyCode) {
+    switch (keyCode) {
+      // Row 1: Q W E R T Y U I O P
+      case 10: return '#';  // Q -> #
+      case 9:  return '1';  // W -> 1
+      case 8:  return '2';  // E -> 2
+      case 7:  return '3';  // R -> 3
+      case 6:  return '(';  // T -> (
+      case 5:  return ')';  // Y -> )
+      case 4:  return '_';  // U -> _
+      case 3:  return '-';  // I -> -
+      case 2:  return '+';  // O -> +
+      case 1:  return '@';  // P -> @
+      
+      // Row 2: A S D F G H J K L
+      case 20: return '*';  // A -> *
+      case 19: return '4';  // S -> 4
+      case 18: return '5';  // D -> 5
+      case 17: return '6';  // F -> 6
+      case 16: return '/';  // G -> /
+      case 15: return ':';  // H -> :
+      case 14: return ';';  // J -> ;
+      case 13: return '\''; // K -> '
+      case 12: return '"';  // L -> "
+      
+      // Row 3: Z X C V B N M
+      case 29: return '7';  // Z -> 7
+      case 28: return '8';  // X -> 8
+      case 27: return '9';  // C -> 9
+      case 26: return '?';  // V -> ?
+      case 25: return '!';  // B -> !
+      case 24: return ',';  // N -> ,
+      case 23: return '.';  // M -> .
+      
+      // Row 4: Mic key -> 0
+      case 34: return '0';  // Mic -> 0
+      
+      default: return 0;
+    }
+  }
+
+public:
+  TCA8418Keyboard(uint8_t addr = 0x34, TwoWire* wire = &Wire) 
+    : _addr(addr), _wire(wire), _initialized(false), 
+      _shiftActive(false), _shiftConsumed(false), _shiftHeld(false), _shiftUsedWhileHeld(false), _altActive(false), _symActive(false), _lastShiftTime(0) {}
+
+  bool begin() {
+    // Check if device responds
+    _wire->beginTransmission(_addr);
+    if (_wire->endTransmission() != 0) {
+      Serial.println("TCA8418: Device not found");
+      return false;
+    }
+
+    // --- Warm-reboot safe init sequence ---
+    // The TCA8418 stays powered across ESP32 resets (no dedicated RST pin),
+    // so the scanner may still be active from the previous session.
+    // We must disable it before reconfiguring the matrix.
+
+    // 1. Disable scanner — stop all scanning before touching config
+    writeReg(TCA8418_REG_CFG, 0x00);
+
+    // 2. Drain any stale events from the previous session
+    for (int i = 0; i < 16; i++) {
+      if ((readReg(TCA8418_REG_KEY_LCK_EC) & 0x0F) == 0) break;
+      readReg(TCA8418_REG_KEY_EVENT_A);
+    }
+    writeReg(TCA8418_REG_INT_STAT, 0x1F);  // Clear all interrupt flags
+
+    // 3. Explicitly clear GPI event masks (prevent phantom GPI events)
+    writeReg(TCA8418_REG_GPI_EM1, 0x00);
+    writeReg(TCA8418_REG_GPI_EM2, 0x00);
+    writeReg(TCA8418_REG_GPI_EM3, 0x00);
+
+    // 4. Configure keyboard matrix (8 rows x 10 cols)
+    writeReg(TCA8418_REG_KP_GPIO1, 0xFF);  // Rows 0-7 as keypad
+    writeReg(TCA8418_REG_KP_GPIO2, 0xFF);  // Cols 0-7 as keypad
+    writeReg(TCA8418_REG_KP_GPIO3, 0x03);  // Cols 8-9 as keypad
+
+    // 5. Set debounce
+    writeReg(TCA8418_REG_DEBOUNCE, 0x03);
+
+    // 6. Final pre-enable cleanup
+    writeReg(TCA8418_REG_INT_STAT, 0x1F);
+
+    // 7. Enable scanner — matrix config is stable, safe to start scanning
+    writeReg(TCA8418_REG_CFG, 0x11);  // KE_IEN + INT_CFG
+
+    // 8. Let scanner stabilise, then flush any spurious first-scan events
+    delay(5);
+    for (int i = 0; i < 16; i++) {
+      if ((readReg(TCA8418_REG_KEY_LCK_EC) & 0x0F) == 0) break;
+      readReg(TCA8418_REG_KEY_EVENT_A);
+    }
+    writeReg(TCA8418_REG_INT_STAT, 0x1F);
+
+    _initialized = true;
+    Serial.println("TCA8418: Keyboard initialized OK");
+    return true;
+  }
+
+  // Read a key press - returns character or 0 if no key
+  char readKey() {
+    if (!_initialized) return 0;
+
+    // Check for key events in FIFO
+    uint8_t keyCount = readReg(TCA8418_REG_KEY_LCK_EC) & 0x0F;
+    if (keyCount == 0) return 0;
+
+    // Read key event from FIFO
+    uint8_t keyEvent = readReg(TCA8418_REG_KEY_EVENT_A);
+
+    // Bit 7: 1 = press, 0 = release
+    bool pressed = (keyEvent & 0x80) != 0;
+    uint8_t keyCode = keyEvent & 0x7F;
+
+    // Clear interrupt
+    writeReg(TCA8418_REG_INT_STAT, 0x1F);
+
+    Serial.printf("KB raw: event=0x%02X code=%d pressed=%d count=%d\n", 
+                  keyEvent, keyCode, pressed, keyCount);
+
+    // Track shift release (before the general release-ignore)
+    if (!pressed && (keyCode == 35 || keyCode == 31)) {
+      _shiftHeld = false;
+      // If shift was used while held (e.g. cursor nav), clear it completely
+      // so the next bare keypress isn't treated as shifted.
+      // If shift was NOT used (tap-then-release), keep _shiftActive for one-shot.
+      if (_shiftUsedWhileHeld) {
+        _shiftActive = false;
+      }
+      _shiftUsedWhileHeld = false;
+      return 0;
+    }
+
+    // Only act on key press, not release
+    if (!pressed || keyCode == 0) {
+      return 0;
+    }
+
+    // Handle modifier keys - set sticky state and return 0
+    if (keyCode == 35 || keyCode == 31) {  // Shift keys
+      _shiftActive = true;
+      _shiftHeld = true;
+      _shiftUsedWhileHeld = false;
+      _lastShiftTime = millis();
+      Serial.println("KB: Shift activated");
+      return 0;
+    }
+    if (keyCode == 30) {  // Alt key
+      _altActive = true;
+      Serial.println("KB: Alt activated");
+      return 0;
+    }
+    if (keyCode == 32) {  // Sym key (bottom row)
+      _symActive = true;
+      Serial.println("KB: Sym activated");
+      return 0;
+    }
+    
+    // Handle dedicated $ key (key code 22, next to M)
+    // Bare press = emoji picker, Sym+$ = literal '$'
+    if (keyCode == 22) {
+      if (_symActive) {
+        _symActive = false;
+        Serial.println("KB: Sym+$ -> '$'");
+        return '$';
+      }
+      Serial.println("KB: $ key -> emoji");
+      return KB_KEY_EMOJI;
+    }
+    
+    // Handle Mic key - always produces '0' (silk-screened on key)
+    // Sym+Mic also produces '0' (consumes sym so it doesn't leak)
+    if (keyCode == 34) {
+      _symActive = false;
+      Serial.println("KB: Mic -> '0'");
+      return '0';
+    }
+
+    // Get the character
+    char c = 0;
+    
+    // Alt+B -> backlight toggle (T-Deck Pro MAX only — working front-light on IO41)
+    if (_altActive && keyCode == 25) {  // keyCode 25 = B
+      _altActive = false;
+      Serial.println("KB: Alt+B -> backlight toggle");
+      return KB_KEY_BACKLIGHT;
+    }
+
+    if (_altActive) {
+      c = getAltChar(keyCode);
+      _altActive = false;  // Reset sticky alt
+      if (c != 0) {
+        Serial.printf("KB: Alt+key -> '%c'\n", c);
+        return c;
+      }
+    }
+    
+    if (_symActive) {
+      c = getSymChar(keyCode);
+      _symActive = false;  // Reset sticky sym
+      if (c != 0) {
+        Serial.printf("KB: Sym+key -> '%c'\n", c);
+        return c;
+      }
+    }
+    
+    c = getKeyChar(keyCode);
+    
+    if (c != 0 && _shiftActive) {
+      // Apply shift - uppercase letters
+      if (c >= 'a' && c <= 'z') {
+        c = c - 'a' + 'A';
+      }
+      // Track that shift was used while physically held
+      if (_shiftHeld) {
+        _shiftUsedWhileHeld = true;
+      }
+      // Only clear shift if it's one-shot (tap), not held down
+      if (!_shiftHeld) {
+        _shiftActive = false;
+      }
+      _shiftConsumed = true; // Record that shift was active for this key
+    } else {
+      _shiftConsumed = false;
+    }
+    
+    if (c != 0) {
+      Serial.printf("KB: code %d -> '%c' (0x%02X)\n", keyCode, c >= 32 ? c : '?', c);
+    } else {
+      Serial.printf("KB: code %d -> UNMAPPED\n", keyCode);
+    }
+    
+    return c;
+  }
+
+  bool isReady() const { return _initialized; }
+  
+  // Check if shift was pressed within the last N milliseconds
+  bool wasShiftRecentlyPressed(unsigned long withinMs = 500) const {
+    return (millis() - _lastShiftTime) < withinMs;
+  }
+  
+  // Check if shift was active when the most recent key was produced
+  // (immune to e-ink refresh timing unlike wasShiftRecentlyPressed)
+  bool wasShiftConsumed() const {
+    return _shiftConsumed;
+  }
+};

variants/lilygo_tdeck_pro_max/platformio.ini

@@ -0,0 +1,232 @@
+; =============================================================================
+; T-Deck Pro MAX V0.1 — Meck Build Environments
+;
+; Hardware: ESP32-S3 + XL9555 I/O expander + combined 4G (A7682E) + Audio (ES8311)
+;
+; Key differences from LilyGo_TDeck_Pro (V1.1):
+;   - Peripheral power controlled via XL9555 (not direct GPIO)
+;   - 4G modem and ES8311 audio coexist (no longer mutually exclusive)
+;   - ES8311 I2C codec replaces PCM5102A (different I2S pins, needs I2C config)
+;   - Several GPIO reassignments (see variant.h for full map)
+;   - 1500 mAh battery (was 1400)
+;   - Working e-ink front-light on IO41
+;
+; WHAT WORKS OUT OF THE BOX:
+;   LoRa mesh, keyboard, e-ink display, GPS, touchscreen, battery management,
+;   SD card, text reader, notes, contacts, channels, settings, discovery,
+;   last heard, repeater admin, web reader (WiFi builds), OTA update.
+;
+; NEEDS ADAPTATION (future work):
+;   - HAS_4G_MODEM: ModemManager uses direct GPIO for MODEM_POWER_EN/PWRKEY
+;     which are XL9555-routed on MAX. Needs board.modemPowerOn() etc.
+;   - MECK_AUDIO_VARIANT: ES8311 needs I2C codec init (PCM5102A didn't).
+;     I2S pins are different. AudiobookPlayerScreen needs ES8311 driver.
+;   - Combined 4G+audio: existing #ifdef guards treat them as mutually
+;     exclusive. Needs restructuring for coexistence.
+; =============================================================================
+
+; ---------------------------------------------------------------------------
+; Base environment for T-Deck Pro MAX
+; ---------------------------------------------------------------------------
+[LilyGo_TDeck_Pro_Max]
+extends = esp32_base
+extra_scripts = post:merge_firmware.py
+board = t-deck_pro_max
+board_build.flash_mode = qio
+board_build.f_flash = 80000000L
+board_build.arduino.memory_type = qio_qspi
+board_upload.flash_size = 16MB
+build_flags =
+  ${esp32_base.build_flags}
+  ${sensor_base.build_flags}
+  ; Include MAX variant first (for variant.h, target.h, TDeckProMaxBoard.h)
+  ; then V1.1 variant (for TDeckBoard.h, which TDeckProMaxBoard inherits from)
+  -I variants/LilyGo_TDeck_Pro_Max
+  -I variants/LilyGo_TDeck_Pro
+  ; Both defines needed: LilyGo_TDeck_Pro for existing UI code guards,
+  ; LilyGo_TDeck_Pro_Max for MAX-specific code paths
+  -D LilyGo_TDeck_Pro
+  -D LilyGo_TDeck_Pro_Max
+  -D HAS_XL9555=1
+  -D HAS_GPS=1
+  -D BOARD_HAS_PSRAM=1
+  -D CORE_DEBUG_LEVEL=1
+  -D FORMAT_SPIFFS_IF_FAILED=1
+  -D FORMAT_LITTLEFS_IF_FAILED=1
+  -D ARDUINO_USB_CDC_ON_BOOT=1
+  -D RADIO_CLASS=CustomSX1262
+  -D WRAPPER_CLASS=CustomSX1262Wrapper
+  -D LORA_TX_POWER=22
+  -D SX126X_DIO2_AS_RF_SWITCH
+  -D SX126X_CURRENT_LIMIT=140
+  -D SX126X_RX_BOOSTED_GAIN=1
+  -D SX126X_DIO3_TCXO_VOLTAGE=2.4f
+  ; LoRa SPI pins (direct GPIO — unchanged from V1.1)
+  -D P_LORA_DIO_1=5
+  -D P_LORA_NSS=3
+  -D P_LORA_RESET=4
+  -D P_LORA_BUSY=6
+  -D P_LORA_SCLK=36
+  -D P_LORA_MISO=47
+  -D P_LORA_MOSI=33
+  ; P_LORA_EN deliberately NOT defined — LoRa power via XL9555 in board.begin()
+  ; GPS pins (direct GPIO — changed from V1.1!)
+  -D ENV_INCLUDE_GPS=1
+  -D ENV_SKIP_GPS_DETECT=1
+  -D PIN_GPS_RX=2
+  -D PIN_GPS_TX=16
+  -D GPS_BAUD_RATE=38400
+  ; Sensor exclusions (same as V1.1)
+  -D ENV_INCLUDE_AHTX0=0
+  -D ENV_INCLUDE_BME280=0
+  -D ENV_INCLUDE_BMP280=0
+  -D ENV_INCLUDE_SHTC3=0
+  -D ENV_INCLUDE_SHT4X=0
+  -D ENV_INCLUDE_LPS22HB=0
+  -D ENV_INCLUDE_INA3221=0
+  -D ENV_INCLUDE_INA219=0
+  -D ENV_INCLUDE_INA226=0
+  -D ENV_INCLUDE_INA260=0
+  -D ENV_INCLUDE_MLX90614=0
+  -D ENV_INCLUDE_VL53L0X=0
+  -D ENV_INCLUDE_BME680=0
+  -D ENV_INCLUDE_BMP085=0
+  ; E-ink display (pin changes from V1.1: RST=9, BL=41)
+  -D USE_EINK
+  -D DISPLAY_CLASS=GxEPDDisplay
+  -D EINK_DISPLAY_MODEL=GxEPD2_310_GDEQ031T10
+  -D EINK_WIDTH=240
+  -D EINK_HEIGHT=320
+  -D EINK_CS=34
+  -D EINK_DC=35
+  -D EINK_RST=9
+  -D EINK_BUSY=37
+  -D EINK_SCLK=36
+  -D EINK_MOSI=33
+  -D EINK_BL=41
+  -D EINK_NOT_HIBERNATE=1
+  ; Battery (1500 mAh on MAX, was 1400 on V1.1)
+  -D HAS_BQ27220=1
+  -D AUTO_SHUTDOWN_MILLIVOLTS=2800
+  ; Display rendering parameters
+  -D EINK_LIMIT_FASTREFRESH=10
+  -D EINK_LIMIT_GHOSTING_PX=2000
+  -D DISPLAY_ROTATION=0
+  -D EINK_ROTATION=0
+  -D EINK_SCALE_X=1.875f
+  -D EINK_SCALE_Y=2.5f
+  -D EINK_X_OFFSET=0
+  -D EINK_Y_OFFSET=5
+  ; Legacy display pin aliases (for GxEPDDisplay.cpp)
+  -D PIN_DISPLAY_CS=34
+  -D PIN_DISPLAY_DC=35
+  -D PIN_DISPLAY_RST=9
+  -D PIN_DISPLAY_BUSY=37
+  -D PIN_DISPLAY_SCLK=36
+  -D PIN_DISPLAY_MISO=-1
+  -D PIN_DISPLAY_MOSI=33
+  -D PIN_DISPLAY_BL=41
+  -D PIN_USER_BTN=0
+  ; Touch (INT is direct GPIO; RST is XL9555, handled by board class)
+  -D HAS_TOUCHSCREEN=1
+  -D CST328_PIN_INT=12
+  -D CST328_PIN_RST=-1
+  -D ARDUINO_LOOP_STACK_SIZE=32768
+build_src_filter = ${esp32_base.build_src_filter}
+  ; Include TDeckBoard.cpp from V1.1 (parent class with BQ27220 code)
+  +<../variants/LilyGo_TDeck_Pro/TDeckBoard.cpp>
+  ; Include MAX variant (target.cpp + TDeckProMaxBoard.cpp)
+  +<../variants/LilyGo_TDeck_Pro_Max>
+  +<helpers/sensors/*.cpp>
+lib_deps =
+  ${esp32_base.lib_deps}
+  ${sensor_base.lib_deps}
+  zinggjm/GxEPD2@^1.5.9
+  adafruit/Adafruit GFX Library@^1.11.0
+  bitbank2/PNGdec@^1.0.1
+  WebServer
+  Update
+
+
+; ===========================================================================
+; Meck MAX builds — LoRa mesh works out of the box on all variants.
+; 4G modem and ES8311 audio need adaptation before they can be enabled.
+; ===========================================================================
+
+; MAX + BLE companion (standard BLE phone bridging)
+; Both 4G + audio hardware present but not yet enabled in firmware.
+; BLE_PIN_CODE limit: MAX_CONTACTS=500 (BLE protocol ceiling).
+[env:meck_max_ble]
+extends = LilyGo_TDeck_Pro_Max
+build_flags =
+  ${LilyGo_TDeck_Pro_Max.build_flags}
+  -I examples/companion_radio/ui-new
+  -D MAX_CONTACTS=500
+  -D MAX_GROUP_CHANNELS=20
+  -D BLE_PIN_CODE=123456
+  -D OFFLINE_QUEUE_SIZE=256
+  -D MECK_WEB_READER=1
+  -D MECK_OTA_UPDATE=1
+  -D FIRMWARE_VERSION='"Meck v1.3.MAX"'
+build_src_filter = ${LilyGo_TDeck_Pro_Max.build_src_filter}
+  +<helpers/esp32/*.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+  +<helpers/ui/GxEPDDisplay.cpp>
+lib_deps =
+  ${LilyGo_TDeck_Pro_Max.lib_deps}
+  densaugeo/base64 @ ~1.4.0
+  https://github.com/schreibfaul1/ESP32-audioI2S.git#2.0.6
+  bitbank2/JPEGDEC
+
+; MAX + WiFi companion (WiFi app bridging — no BLE, higher contact limit)
+; WiFi credentials loaded from SD card (/web/wifi.cfg).
+; Connect via MeshCore web app, meshcore.js, or Python CLI.
+[env:meck_max_wifi]
+extends = LilyGo_TDeck_Pro_Max
+build_flags =
+  ${LilyGo_TDeck_Pro_Max.build_flags}
+  -I examples/companion_radio/ui-new
+  -D MAX_CONTACTS=1500
+  -D MAX_GROUP_CHANNELS=20
+  -D MECK_WIFI_COMPANION=1
+  -D TCP_PORT=5000
+  -D WIFI_DEBUG_LOGGING=1
+  -D OFFLINE_QUEUE_SIZE=256
+  -D MECK_WEB_READER=1
+  -D MECK_OTA_UPDATE=1
+  -D FIRMWARE_VERSION='"Meck v1.3.MAX.WiFi"'
+build_src_filter = ${LilyGo_TDeck_Pro_Max.build_src_filter}
+  +<helpers/esp32/*.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+  +<helpers/ui/GxEPDDisplay.cpp>
+lib_deps =
+  ${LilyGo_TDeck_Pro_Max.lib_deps}
+  densaugeo/base64 @ ~1.4.0
+  https://github.com/schreibfaul1/ESP32-audioI2S.git#2.0.6
+  bitbank2/JPEGDEC
+
+; MAX standalone (no BLE/WiFi — maximum battery life, LoRa mesh only)
+; Contacts in PSRAM (1500 capacity). OTA enabled (WiFi AP on demand).
+[env:meck_max_standalone]
+extends = LilyGo_TDeck_Pro_Max
+build_flags =
+  ${LilyGo_TDeck_Pro_Max.build_flags}
+  -I examples/companion_radio/ui-new
+  -D MAX_CONTACTS=1500
+  -D MAX_GROUP_CHANNELS=20
+  -D OFFLINE_QUEUE_SIZE=1
+  -D MECK_OTA_UPDATE=1
+  -D FIRMWARE_VERSION='"Meck v1.3.MAX.SA"'
+build_src_filter = ${LilyGo_TDeck_Pro_Max.build_src_filter}
+  +<helpers/esp32/*.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+  +<helpers/ui/GxEPDDisplay.cpp>
+lib_deps =
+  ${LilyGo_TDeck_Pro_Max.lib_deps}
+  densaugeo/base64 @ ~1.4.0

variants/lilygo_tdeck_pro_max/target.cpp

@@ -0,0 +1,91 @@
+#include <Arduino.h>
+#include "variant.h"
+#include "target.h"
+
+TDeckProMaxBoard board;
+
+#if defined(P_LORA_SCLK)
+  static SPIClass loraSpi(HSPI);
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY, loraSpi);
+#else
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY);
+#endif
+
+WRAPPER_CLASS radio_driver(radio, board);
+
+ESP32RTCClock fallback_clock;
+AutoDiscoverRTCClock rtc_clock(fallback_clock);
+
+#if HAS_GPS
+  // Wrap Serial2 with a sentence counter so the UI can show NMEA throughput.
+  // MicroNMEALocationProvider reads through this wrapper transparently.
+  GPSStreamCounter gpsStream(Serial2);
+  MicroNMEALocationProvider gps(gpsStream, &rtc_clock);
+  EnvironmentSensorManager sensors(gps);
+#else
+  SensorManager sensors;
+#endif
+
+#ifdef DISPLAY_CLASS
+  DISPLAY_CLASS display;
+  MomentaryButton user_btn(PIN_USER_BTN, 1000, true);
+#endif
+
+bool radio_init() {
+  MESH_DEBUG_PRINTLN("radio_init() - starting");
+  
+  // NOTE: board.begin() is called by main.cpp setup() before radio_init()
+  // I2C is already initialized there with correct pins
+  
+  fallback_clock.begin();
+  MESH_DEBUG_PRINTLN("radio_init() - fallback_clock started");
+  
+  // Wire already initialized in board.begin() - just use it for RTC
+  rtc_clock.begin(Wire);
+  MESH_DEBUG_PRINTLN("radio_init() - rtc_clock started");
+
+#if defined(P_LORA_SCLK)
+  MESH_DEBUG_PRINTLN("radio_init() - initializing LoRa SPI...");
+  loraSpi.begin(P_LORA_SCLK, P_LORA_MISO, P_LORA_MOSI, P_LORA_NSS);
+  MESH_DEBUG_PRINTLN("radio_init() - SPI initialized, calling radio.std_init()...");
+  bool result = radio.std_init(&loraSpi);
+  MESH_DEBUG_PRINTLN("radio_init() - radio.std_init() returned: %s", result ? "SUCCESS" : "FAILED");
+  return result;
+#else
+  MESH_DEBUG_PRINTLN("radio_init() - calling radio.std_init() without custom SPI...");
+  bool result = radio.std_init();
+  return result;
+#endif
+}
+
+uint32_t radio_get_rng_seed() {
+  return radio.random(0x7FFFFFFF);
+}
+
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr) {
+  radio.setFrequency(freq);
+  radio.setSpreadingFactor(sf);
+  radio.setBandwidth(bw);
+  radio.setCodingRate(cr);
+
+  // Longer preamble for low SF improves reliability — each symbol is shorter
+  // at low SF, so more symbols are needed for reliable detection.
+  // SF <= 8 gets 32 symbols (~65ms at SF7/62.5kHz); SF >= 9 keeps 16 (already ~131ms+).
+  // See: https://github.com/meshcore-dev/MeshCore/pull/1954
+  uint16_t preamble = (sf <= 8) ? 32 : 16;
+  radio.setPreambleLength(preamble);
+  MESH_DEBUG_PRINTLN("radio_set_params() - bw=%.1f sf=%u preamble=%u", bw, sf, preamble);
+}
+
+void radio_set_tx_power(uint8_t dbm) {
+  radio.setOutputPower(dbm);
+}
+
+mesh::LocalIdentity radio_new_identity() {
+  RadioNoiseListener rng(radio);
+  return mesh::LocalIdentity(&rng);
+}
+
+void radio_reset_agc() {
+  radio.setRxBoostedGainMode(true);
+}

variants/lilygo_tdeck_pro_max/target.h

@@ -0,0 +1,47 @@
+#pragma once
+
+// Include variant.h first to ensure all board-specific defines are available
+#include "variant.h"
+
+#define RADIOLIB_STATIC_ONLY 1
+#include <RadioLib.h>
+#include <helpers/radiolib/RadioLibWrappers.h>
+#include <helpers/radiolib/CustomSX1262Wrapper.h>
+#include <TDeckProMaxBoard.h>
+#include <helpers/AutoDiscoverRTCClock.h>
+
+#ifdef DISPLAY_CLASS
+  #include <helpers/ui/GxEPDDisplay.h>
+  #include <helpers/ui/MomentaryButton.h>
+#endif
+
+#if HAS_GPS
+  #include "helpers/sensors/EnvironmentSensorManager.h"
+  #include "helpers/sensors/MicroNMEALocationProvider.h"
+  #include "GPSStreamCounter.h"
+#else
+  #include <helpers/SensorManager.h>
+#endif
+
+extern TDeckProMaxBoard board;
+extern WRAPPER_CLASS radio_driver;
+extern AutoDiscoverRTCClock rtc_clock;
+
+#if HAS_GPS
+  extern GPSStreamCounter gpsStream;
+  extern EnvironmentSensorManager sensors;
+#else
+  extern SensorManager sensors;
+#endif
+
+#ifdef DISPLAY_CLASS
+  extern DISPLAY_CLASS display;
+  extern MomentaryButton user_btn;
+#endif
+
+bool radio_init();
+uint32_t radio_get_rng_seed();
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr);
+void radio_set_tx_power(uint8_t dbm);
+mesh::LocalIdentity radio_new_identity();
+void radio_reset_agc();

variants/lilygo_tdeck_pro_max/variant.h

@@ -0,0 +1,301 @@
+#pragma once
+
+// =============================================================================
+// LilyGo T-Deck Pro MAX V0.1 - Pin Definitions
+// Hardware revision: HD-V3-250911
+//
+// KEY DIFFERENCES FROM T-Deck Pro V1.1:
+//   - XL9555 I/O expander (0x20) controls peripheral power, resets, and switches
+//     (LoRa EN, GPS EN, modem power, touch RST, keyboard RST, antenna sel, etc.)
+//   - 4G (A7682E) and audio (ES8311) coexist on ONE board — no longer mutually exclusive
+//   - ES8311 I2C codec replaces PCM5102A (needs I2C config, different I2S pins)
+//   - E-ink RST moved: IO9 (was IO16)
+//   - E-ink BL moved: IO41 (was IO45, now has working front-light hardware!)
+//   - GPS UART moved: RX=IO2, TX=IO16 (was RX=IO44, TX=IO43)
+//   - GPS/LoRa power via XL9555 (was direct GPIO 39/46)
+//   - Touch RST via XL9555 IO07 (was GPIO 38)
+//   - Modem power/PWRKEY via XL9555 (was direct GPIO 41/40)
+//   - No PIN_PERF_POWERON (IO10 is now modem UART RX)
+//   - Battery: 1500 mAh (was 1400 mAh)
+//   - LoRa antenna switch (SKY13453) controlled by XL9555 IO04
+//   - Audio output mux (A7682E vs ES8311) controlled by XL9555 IO12
+//   - Speaker amplifier (NS4150B) enable via XL9555 IO06
+// =============================================================================
+
+// -----------------------------------------------------------------------------
+// E-Ink Display (GDEQ031T10 - 240x320)
+// E-ink SHARES the SPI bus with LoRa and SD card (SCK=36, MOSI=33, MISO=47)
+// They use different chip selects: E-ink CS=34, LoRa CS=3, SD CS=48
+// -----------------------------------------------------------------------------
+#define PIN_EINK_CS    34
+#define PIN_EINK_DC    35
+#define PIN_EINK_RES    9    // MAX: IO9 (was IO16 on V1.1)
+#define PIN_EINK_BUSY  37
+#define PIN_EINK_SCLK  36    // Shared with LoRa + SD
+#define PIN_EINK_MOSI  33    // Shared with LoRa + SD
+#define PIN_EINK_BL    41    // MAX: IO41 — working front-light! (was IO45 non-functional on V1.1)
+
+// Legacy aliases for MeshCore compatibility
+#define PIN_DISPLAY_CS    PIN_EINK_CS
+#define PIN_DISPLAY_DC    PIN_EINK_DC
+#define PIN_DISPLAY_RST   PIN_EINK_RES
+#define PIN_DISPLAY_BUSY  PIN_EINK_BUSY
+#define PIN_DISPLAY_SCLK  PIN_EINK_SCLK
+#define PIN_DISPLAY_MOSI  PIN_EINK_MOSI
+
+// Display dimensions - native resolution of GDEQ031T10
+#define LCD_HOR_SIZE 240
+#define LCD_VER_SIZE 320
+
+// E-ink model for GxEPD2
+#define EINK_DISPLAY_MODEL GxEPD2_310_GDEQ031T10
+
+// -----------------------------------------------------------------------------
+// SPI Bus - Shared by LoRa, SD Card, AND E-ink display
+// -----------------------------------------------------------------------------
+#define BOARD_SPI_SCLK 36
+#define BOARD_SPI_MISO 47
+#define BOARD_SPI_MOSI 33
+
+// -----------------------------------------------------------------------------
+// I2C Bus
+// -----------------------------------------------------------------------------
+#define I2C_SDA 13
+#define I2C_SCL 14
+
+// Aliases for ESP32Board base class compatibility
+#define PIN_BOARD_SDA I2C_SDA
+#define PIN_BOARD_SCL I2C_SCL
+
+// I2C Device Addresses
+#define I2C_ADDR_ES8311     0x18  // ES8311 audio codec (NEW on MAX)
+#define I2C_ADDR_TOUCH      0x1A  // CST328
+#define I2C_ADDR_XL9555     0x20  // XL9555 I/O expander (NEW on MAX)
+#define I2C_ADDR_GYROSCOPE  0x28  // BHI260AP
+#define I2C_ADDR_KEYBOARD   0x34  // TCA8418
+#define I2C_ADDR_BQ27220    0x55  // Fuel gauge
+#define I2C_ADDR_DRV2605    0x5A  // Motor driver (haptic)
+#define I2C_ADDR_BQ25896    0x6B  // Charger
+
+// -----------------------------------------------------------------------------
+// XL9555 I/O Expander — Pin Assignments
+//
+// The XL9555 replaces direct GPIO control of peripheral power enables,
+// resets, and switches. It must be initialised over I2C before LoRa, GPS,
+// modem, or touch can be used.
+//
+// Port 0: pins 0-7, registers 0x02 (output) / 0x06 (direction)
+// Port 1: pins 8-15, registers 0x03 (output) / 0x07 (direction)
+// Direction: 0 = output, 1 = input
+// -----------------------------------------------------------------------------
+#define HAS_XL9555 1
+
+// XL9555 I2C registers
+#define XL9555_REG_INPUT_0   0x00
+#define XL9555_REG_INPUT_1   0x01
+#define XL9555_REG_OUTPUT_0  0x02
+#define XL9555_REG_OUTPUT_1  0x03
+#define XL9555_REG_INVERT_0  0x04
+#define XL9555_REG_INVERT_1  0x05
+#define XL9555_REG_CONFIG_0  0x06   // 0=output, 1=input
+#define XL9555_REG_CONFIG_1  0x07
+
+// XL9555 pin assignments (0-7 = Port 0, 8-15 = Port 1)
+#define XL_PIN_6609_EN       0    // HIGH: Enable A7682E power supply (SGM6609 boost)
+#define XL_PIN_LORA_EN       1    // HIGH: Enable SX1262 power supply
+#define XL_PIN_GPS_EN        2    // HIGH: Enable GPS power supply
+#define XL_PIN_1V8_EN        3    // HIGH: Enable BHI260AP 1.8V power supply
+#define XL_PIN_LORA_SEL      4    // HIGH: internal antenna, LOW: external antenna (SKY13453)
+#define XL_PIN_MOTOR_EN      5    // HIGH: Enable DRV2605 power supply
+#define XL_PIN_AMPLIFIER     6    // HIGH: Enable NS4150B speaker power amplifier
+#define XL_PIN_TOUCH_RST     7    // LOW: Reset touch controller (active-low)
+#define XL_PIN_PWRKEY_EN     8    // HIGH: A7682E POWERKEY toggle
+#define XL_PIN_KEY_RST       9    // LOW: Reset keyboard (active-low)
+#define XL_PIN_AUDIO_SEL    10    // HIGH: A7682E audio out, LOW: ES8311 audio out
+// Pins 11-15 are reserved
+
+// Default XL9555 output state at boot (all power enables ON, resets de-asserted)
+// Bit layout: [P07..P00] = TOUCH_RST=1, AMP=0, MOTOR_EN=0, LORA_SEL=1, 1V8=1, GPS=1, LORA=1, 6609=0
+//             [P17..P10] = reserved=0, AUDIO_SEL=0, KEY_RST=1, PWRKEY=0
+//
+// Conservative boot defaults for Meck:
+//   - LoRa ON, GPS ON, 1.8V ON, internal antenna
+//   - Modem OFF (6609_EN LOW), PWRKEY LOW (toggled later if needed)
+//   - Motor OFF, Amplifier OFF (saves power, enabled on demand)
+//   - Touch RST HIGH (not resetting), Keyboard RST HIGH (not resetting)
+//   - Audio select LOW (ES8311 by default — Meck controls this when needed)
+#define XL9555_BOOT_PORT0  0b10011110  // 0x9E: T_RST=1, AMP=0, MOT=0, LSEL=1, 1V8=1, GPS=1, LORA=1, 6609=0
+#define XL9555_BOOT_PORT1  0b00000010  // 0x02: ..., ASEL=0, KRST=1, PKEY=0
+
+// -----------------------------------------------------------------------------
+// Touch Controller (CST328)
+// NOTE: Touch RST is via XL9555 pin 7, NOT a direct GPIO!
+// CST328_PIN_RST is defined as -1 to signal "not a direct GPIO".
+// The board class handles touch reset via XL9555 in begin().
+// -----------------------------------------------------------------------------
+#define HAS_TOUCHSCREEN 1
+#define CST328_PIN_INT 12
+#define CST328_PIN_RST -1     // MAX: Routed through XL9555 IO07 — handled by board class
+
+// -----------------------------------------------------------------------------
+// GPS
+// NOTE: GPS power enable is via XL9555 pin 2, NOT a direct GPIO!
+// PIN_GPS_EN is intentionally NOT defined — the board class handles it via XL9555.
+// -----------------------------------------------------------------------------
+#define HAS_GPS 1
+#define GPS_BAUDRATE 38400
+// #define PIN_GPS_EN — NOT a direct GPIO on MAX (XL9555 IO02)
+#define GPS_RX_PIN  2         // MAX: IO2 (was IO44 on V1.1) — ESP32 receives from GPS
+#define GPS_TX_PIN 16         // MAX: IO16 (was IO43 on V1.1) — ESP32 sends to GPS
+#define PIN_GPS_PPS  1
+
+// -----------------------------------------------------------------------------
+// Buttons & Controls
+// -----------------------------------------------------------------------------
+#define BUTTON_PIN 0
+#define PIN_USER_BTN 0
+
+// Vibration Motor — DRV2605 driver (same as V1.1)
+// Motor power enable is via XL9555 pin 5, not a direct GPIO.
+#define HAS_DRV2605 1
+
+// -----------------------------------------------------------------------------
+// SD Card
+// -----------------------------------------------------------------------------
+#define HAS_SDCARD
+#define SDCARD_USE_SPI1
+#define SPI_MOSI 33
+#define SPI_SCK  36
+#define SPI_MISO 47
+#define SPI_CS   48
+#define SDCARD_CS SPI_CS
+
+// -----------------------------------------------------------------------------
+// Keyboard (TCA8418)
+// NOTE: Keyboard RST is via XL9555 pin 9 (active-low).
+// The board class handles keyboard reset via XL9555 in begin().
+// -----------------------------------------------------------------------------
+#define KB_BL_PIN 42
+#define BOARD_KEYBOARD_INT 15
+#define HAS_PHYSICAL_KEYBOARD 1
+
+// -----------------------------------------------------------------------------
+// Audio — ES8311 I2C Codec (NEW on MAX — replaces PCM5102A)
+//
+// ES8311 is an I2C-controlled audio codec (unlike PCM5102A which needed no config).
+// It requires I2C register setup for input source, gain, volume, etc.
+// Speaker/headphone output is shared with A7682E modem audio, selected via
+// XL9555 pin AUDIO_SEL: LOW = ES8311, HIGH = A7682E.
+// Power amplifier (NS4150B) for speaker enabled via XL9555 pin AMPLIFIER.
+//
+// I2S pin mapping for ES8311 (completely different from V1.1 PCM5102A!):
+//   MCLK  = IO38  (master clock — ES8311 needs this, PCM5102A didn't)
+//   SCLK  = IO39  (bit clock, aka BCLK)
+//   LRCK  = IO18  (word select, aka LRC/WS)
+//   DSDIN = IO17  (DAC serial data in — ESP32 sends audio TO codec)
+//   ASDOUT= IO40  (ADC serial data out — codec sends mic audio TO ESP32)
+// -----------------------------------------------------------------------------
+#define HAS_ES8311_AUDIO 1
+
+#define BOARD_ES8311_MCLK   38
+#define BOARD_ES8311_SCLK   39
+#define BOARD_ES8311_LRCK   18
+#define BOARD_ES8311_DSDIN  17    // ESP32 → ES8311 (speaker/headphone output)
+#define BOARD_ES8311_ASDOUT 40    // ES8311 → ESP32 (microphone input)
+
+// Compatibility aliases for ESP32-audioI2S library (setPinout expects BCLK, LRC, DOUT)
+#define BOARD_I2S_BCLK  BOARD_ES8311_SCLK    // IO39
+#define BOARD_I2S_LRC   BOARD_ES8311_LRCK    // IO18
+#define BOARD_I2S_DOUT  BOARD_ES8311_DSDIN   // IO17
+#define BOARD_I2S_MCLK  BOARD_ES8311_MCLK    // IO38 (ESP32-audioI2S may need setMCLK)
+
+// Microphone — ES8311 built-in ADC (replaces separate PDM mic on V1.1)
+// Mic data comes through I2S ASDOUT pin, not a separate PDM interface.
+#define BOARD_MIC_I2S_DIN BOARD_ES8311_ASDOUT // IO40
+
+// -----------------------------------------------------------------------------
+// Sensors
+// -----------------------------------------------------------------------------
+#define HAS_BHI260AP        // Gyroscope/IMU (1.8V power via XL9555 IO03)
+#define BOARD_GYRO_INT 21
+
+// -----------------------------------------------------------------------------
+// Power Management
+// -----------------------------------------------------------------------------
+#define HAS_BQ27220 1
+#define BQ27220_I2C_ADDR 0x55
+#define BQ27220_I2C_SDA I2C_SDA
+#define BQ27220_I2C_SCL I2C_SCL
+#define BQ27220_DESIGN_CAPACITY 1500    // MAX: 1500 mAh (was 1400 on V1.1)
+#define BQ27220_DESIGN_CAPACITY_MAH 1500 // Alias used by TDeckBoard.h
+
+#define HAS_PPM 1
+#define XPOWERS_CHIP_BQ25896
+
+// -----------------------------------------------------------------------------
+// LoRa Radio (SX1262)
+// NOTE: LoRa power enable is via XL9555 pin 1, NOT GPIO 46!
+// The board class enables LoRa power via XL9555 in begin().
+// P_LORA_EN is intentionally NOT defined here — handled by board class.
+// Antenna selection: XL9555 pin 4 (HIGH=internal, LOW=external via SKY13453).
+// -----------------------------------------------------------------------------
+#define USE_SX1262
+#define USE_SX1268
+
+// LORA_EN is NOT a direct GPIO on MAX — omit the define entirely.
+// If any code references P_LORA_EN, it must be guarded with #ifndef HAS_XL9555.
+// #define LORA_EN  — NOT DEFINED (was GPIO 46 on V1.1)
+
+#define LORA_SCK   36
+#define LORA_MISO  47
+#define LORA_MOSI  33   // Shared with e-ink and SD card
+#define LORA_CS    3
+#define LORA_RESET 4
+#define LORA_DIO0  -1   // Not connected on SX1262
+#define LORA_DIO1  5    // SX1262 IRQ
+#define LORA_DIO2  6    // SX1262 BUSY
+
+// SX126X driver aliases (Meshtastic compatibility)
+#define SX126X_CS    LORA_CS
+#define SX126X_DIO1  LORA_DIO1
+#define SX126X_BUSY  LORA_DIO2
+#define SX126X_RESET LORA_RESET
+
+// RadioLib/MeshCore compatibility aliases
+#define P_LORA_NSS    LORA_CS
+#define P_LORA_DIO_1  LORA_DIO1
+#define P_LORA_RESET  LORA_RESET
+#define P_LORA_BUSY   LORA_DIO2
+#define P_LORA_SCLK   LORA_SCK
+#define P_LORA_MISO   LORA_MISO
+#define P_LORA_MOSI   LORA_MOSI
+// P_LORA_EN is NOT defined — LoRa power is via XL9555, handled in board begin()
+
+// -----------------------------------------------------------------------------
+// 4G Modem — A7682E (ALWAYS PRESENT on MAX — no longer optional!)
+//
+// On V1.1, 4G and audio were mutually exclusive hardware configurations.
+// On MAX, both coexist. The XL9555 controls:
+//   - 6609_EN (XL pin 0): modem power supply (SGM6609 boost converter)
+//   - PWRKEY (XL pin 8): modem power key toggle
+// Audio output from modem vs ES8311 is selected by AUDIO_SEL (XL pin 10).
+//
+// MODEM_POWER_EN and MODEM_PWRKEY are NOT direct GPIOs — ModemManager
+// needs MAX-aware paths (see integration guide).
+// MODEM_RST does not exist on MAX (IO9 is now LCD_RST).
+// -----------------------------------------------------------------------------
+// Direct GPIO modem pins (still accessible as regular GPIO):
+#define MODEM_RI   7     // Ring indicator (interrupt input)
+#define MODEM_DTR  8     // Data terminal ready (output)
+#define MODEM_RX  10     // UART RX (ESP32 receives from modem)
+#define MODEM_TX  11     // UART TX (ESP32 sends to modem)
+
+// XL9555-routed modem pins — these are NOT direct GPIO!
+// MODEM_POWER_EN and MODEM_PWRKEY are intentionally NOT defined.
+// Existing code guarded by #ifdef MODEM_POWER_EN / #ifdef HAS_4G_MODEM will
+// be skipped. Use board.modemPowerOn()/modemPwrkeyPulse() instead.
+// MODEM_RST does not exist on MAX (IO9 is LCD_RST).
+
+// Compatibility: PIN_PERF_POWERON does not exist on MAX (IO10 is modem UART RX).
+// Defined as -1 so TDeckBoard.cpp compiles (parent class), but never used at runtime.
+#define PIN_PERF_POWERON -1